1. Field of the Invention
The field of this invention relates generally toward cutting blades for saws and particularly toward a specialized slot that significantly reduces thermal cracking.
2. Description of the Prior Art
Circular saw blades typically have a series of tips around the perimeter that are reinforced with a cutting material to aid with the cutting of hard surfaces, such as concrete and the like. These tips are cut into the plate and reinforced with a strong cutting material, such as diamonds or carbide, which are then added to the tips using high temperatures.
These series of tips are often separated by lasered slots that provide a means for the reduction of stress to the blade during use. Such stresses include deformation and strain caused from the heat generated during use. Often this thermal strain is sufficient enough to crack the blade and reduce or eliminate its utility. Prior art slots that have shown some effectiveness are slots that are vertically oriented from the perimeter of the blade and toward the center of the blade. One prior art modification has this vertical slot terminating in a semi-circular curve with two holes at the end of side of the semi-circular curve.
However, these blades, also referred to as cores, are susceptible to cracking in hard aggregate conditions. The cracks have occurred in two failure modes. The first mode has the crack initating at the apex of the furthermost side of the aforementioned slot that includes the semi-circular curve and propagating tangentially to the closest apex of an adjacent slot. The second mode initiates near the base of the aforementioned slot that includes the semi-circular curve and propagates at approximately a 60 degree angle towards the center of the blade, toward the whole where the blade mounts to an arbor.
There exists a need for an improved slot that reduces or eliminates the thermal cracking seen in prior art slots.